Pad Name

I/O

Options

Description

RT/GT

I/O

¾

Tone acquisition time and release time can be set through connection

with external resistor and capacitor CMOS IN/OUT

EST

O

¾

Early steering output CMOS out

VP

I

¾

Operational amplifier non-inverting input

VN

I

¾

Operational amplifier inverting input

GS

O

¾

Operational amplifier output terminal

VREF

O

¾

X1

X2

I

O

¾

X1 and X2 are connected to an external 32768Hz crystal or resonator for

the system clock.

XC

¾¾

External low pass filter pin used for the frequency up conversion circuit.

RES

I

¾

Schmitt trigger reset input. Active low.

VDD

¾¾

Positive power supply

VSS

¾¾

Negative power supply, ground.

VDD2

¾¾

DTMF receiver positive power supply

VSS2

¾¾

DTMF receiver negative power supply

Note:

Each pin on PA can be programmed through a configuration option to have a wake-up function.

HT95R43/HT95R44

Rev. 1.00

4

March 31, 2010